Optimization of the co-combustion of coal and composite biomass pellets

Abstract

Abstract Composite biomass pellets (CBPs) are made from catkins, wood waste, and rice straw in China. This paper presents studies on the co-combustion of CBPs and coal by thermogravimetric analyzer and fluidized bed. The combustion parameters indicate that the co-combustion performance is improved gradually with the increase in CBP proportion. The interaction between coal and CBPs at high temperature is significant. The thermogravimetry and differential thermogravimetry (TG-DTG) curves shift toward a high temperature, and the decomposition process is delayed at high heating rates. The CBP blending ratio of 30% is considered the optimum ratio for coal and CBPs, in accordance with the minimum activation energy and slagging problem. The addition of CBPs can reduce the emission of polycyclic aromatic hydrocarbons (PAHs) and trace metals. The capture of trace metals is related to the alkali metals in ash, and the variation of PAHs is mainly attributed to combustion temperature and fuel properties.